Tracking antenna systems are especially suitable for use aboard ships to track communications satellites while accommodating for roll, pitch, yaw, and turning motions of a ship at sea. For such systems to operate effectively they must point one or more antennae continuously and accurately toward a respective satellite.
For two decades, Sea Tel, Inc. has manufactured antenna systems of the type described in U.S. Pat. No. 5,419,521 to Matthews. Such antenna systems have a three-axis pedestal and employ a “Level Platform” or “Level Cage” in order to provide an accurate and stable horizontal reference for directing servo stabilized antenna controls to accurately track communications satellites.
Tracking antenna systems are especially well suited for the reception and transmission of satellite communication signals, which are typically in the C-band or the Ku-band, each band having its relative strengths and weaknesses. For example, C-band signals are susceptible to terrestrial interference, while Ku-band signals are affected by rain and ice crystals. Accordingly, it is desirable for an antenna system to be configured for operation in both C-band and Ku-band frequency ranges.
One such system is described in U.S. Pat. No. 9,000,995 (995 patent), which describes various systems that include a large primary reflector for C-band satellites and a smaller secondary reflector for Ku-band satellites (see, e.g., '995 patent, FIGS. 15 and 16). Such systems are switchable such that the primary reflector is aligned with and tracks a C-band satellite in a C-band mode, and the secondary reflector is aligned with and tracks a Ku-band satellite in a Ku-band mode.
While such systems are compatible with known and planned satellite communication networks, one will appreciate that an antenna system having a single reflector that is configured to operate at both C-band and Ku-band signals would be desirable.